Door latch



NOW 1968 o. R. WOLFSLAYER 3,409,321

DOOR LATCH Filed Dec. 30, 1964 5 Sheets-Sheet 1 INVENTOR.

,Ua 774g K lf/affs/dycr WWW 7 H77 dFNE/i Nov. 5, 1968 D. R. WOLFSLAYER DOOR LATCH 5 Sheets$heet 2 Filed Dec. 30, 1964 fldh'd/j K wfig i g ex United States Patent Oce 3,409,321 Patented Nov. 5, 1968 3,409,321 DOOR LATCH Donald R. Wolfslayer, Bloomfield Hills, Mich., assignor to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Filed Dec. 30, 1964, Ser. No. 422,459 13 Claims. (Cl. 292-216) ABSTRACT OF THE DISCLOSURE A motor vehicle door latch wherein the rotary bolt has two separate teeth and two separate detents or pawls are provided, one for coaction with each tooth on the rotor. The detents are arranged so that, as the door is closed, first one of the detents falls into the trace of the radial face of the corresponding tooth and thereafter, with further closing movement of the door, the other detent falls into the trace of the radial face of the second tooth.

This invention relates to a mechanism for latching a Swinging member to a fixed member; more particularly, it relates to a door latch for an automobile.

In a typical automobile door latch, a bolt is moved in response to closing of the door and a detent coacts with a ratchet tooth on the bolt to prevent return movement of the latter. Most latches today are of the safety type in which two ratchet teeth are provided serially on the bolt so that if the detent shakes loose from one tooth, as for example in an accident, it may still be engaged by the second or safety tooth to prevent opening of the door. This arrangement, while an improvement in many respects over the single tooth latch, is objectionable in many respects.

It is objectionable from a noise standpoint since the detent, in riding over one ratchet tooth and then the other during closing of the door, slaps rather harshly and erratically against the bolt.

Also, because of the bouncing movement which the detent undergoes in skipping over the successive teeth, the detent sometimes fails to firmly catch on the tooth defining the fully latched position but rather hangs up on the edge of that tooth where, although for all outward appearances it seems to be firmly caught, it may readily be jarred loose from the tooth to allow the door to move toward its open position.

Further, it has sometimes been found that the single detent, when shaken loose from the first or fully latched tooth, as in an accident, also skips over and past the second or safety tooth to allow the door to open fully and allow the passengers to be thrown out of the automobile.

Accordingly, it is an object of the present invention to provide a latch for doors and the like swinging members which will function to prevent opening of the door even when severely jolted.

Another object is to provide a swinging members which will be known latches.

A further object is to provide a latch for doors and like swinging members which will function to positively and fully latch the door with each closing movement.

Yet another object is to provide a latch for a door or like swinging member which will be simple in construction, inexpensive to manufacture, and durable in operation.

latch for doors and like quieter in operation than A more specific object is to provide a latch for an automobile door which will be more crash resistant than known latches.

Another more specific object is to provide a latch for an automobile door which will be quieter in operation than known automobile door latches.

These objects are accomplished according to the present invention by the provision of a latch mechanism having two separate detents, one for coaction with the tooth formation on the bolt defining the safety position and the other for coaction with the tooth formation defining the fully latched position. The detents are arranged so that, as the door is closed, first one of the detents falls into the trace of the radial face of the safety tooth formation and thereafter, with further closing movement of the door, the other detent falls into the trace of the radial face of the fully latched tooth formation. Thus, the safety detent has been moved well beyond the radial face of the safety tooth formation by the time the second detent catches on the fully latched tooth formation, thereby assuring that it will not be hung up on the safety tooth formation but rather will be firmly planted in the path of that tooth. Therefore, even if the second detent should hang up on the edge of the fully latched tooth upon closing of the door and thereafter be shaken loose from that tooth to release the bolt, the bolt will be positively caught by the subsequent firm abutment of the first or safety detent with the radial face of the safety tooth formation.

According to another feature of the invention, means are provided to gradually decelerate each detent as it falls or is urged into the trace of the related tooth formation. These means, which may for example comprise a pad of cushioning material for each detent arranged to intercept that detent after it has fallen into the trace of the related tooth, prevent the detents from slapping against the bolt as they fall into the trace of the related tooth and hereby provide quiet latch operation. Latch noise is further reduced by the fact that, with a separate detent for coaction with each tooth formation, the noise of the single detent of the prior art devices skipping over and slapping against first one tooth and then the other is completely eliminated.

Further, and according to another feature of the invention, the surface of each tooth preceding the radial tooth face is shaped as a circular arc about the axis of rotation of the bolt, so that the detents slide smoothly and without vertical displacement along the respective tooth formations prior to dropping into place. This feature eliminates most of the dynamic force factors present in the prior single detent constructions, thereby prolonging effective latch life and assuring that the detents will drop smoothly into their latching positions even under widely varying operational and/or climatic conditions.

These and other objects, features, and advantages of the invention will become apparent from the following detailed description of a preferred embodiment of the invention and from the accompanying drawings in which:

FIGURE 1 is a fragmentary view of an automobile with the right front door shown in an open position to reveal the mounting in the door of a door latch constructed according to the invention;

FIGURE 2 is a fragmentary end elevational view on an enlarged scale of the door latch of FIGURE 1 showing the latch in its unlatched condition;

FIGURE 3 is a view similar to FIGURE 2 but showing the latch in its latched condition; and

FIGURE 4 is a side elevational view of the latch o FIGURES 2 and 3, the latch appearing in its unlatched condition.

Referring first to FIGURE 1, the latch of the invention, broadly considered, comprises a striker rigidly extending from door post 12 and an assembly 14 mounted within door 16 and exposed, by a tapered slot 18 in door panel 19, for coaction with striker 10 upon closing of the door.

Striker 10 includes a cylindrical shank portion 20 and a cylindrical flange portion 22.

Referring now to FIGURE 2, door assembly 14 includes a bolt or rotor 24 mounted for pivotal movement on a pin 26 secured to the door frame. Bolt or rotor 24 is shaped to define a latch arm 28 and a throwout arm 30 defining therebetween a slot or throat 32. As door 16 is closed, shank portion 20 of striker 10 is guided by slot 18 into engagement with throwout arm 30, whereby to pivot rotor 24 about the axis of pin 26 and move latch arm 28 around shank portion 20, as seen in FIGURE 3, to trap latch portion 20 within throat 32. A spring 25 resists such pivotal movement of rotor 24.

During this closing operation, flange portion 22 of striker 10 slides along the inclined upper face of a wedge block 34 mounted for sliding movement in a direction slid inwardly a slight amount against the resistance of a compression spring 38 coiled around rod 36. Thus, with the door shut, the wedge is urged by spring 38 firmly against flange portion 22 so that the wedge coacts with rotor 24 to trap striker 10.

Referring again to FIGURE 2, rotor or bolt 24 presents first and second substantially radial faces 40 and 42 for coaction with first and second detents 44 and 46. As will be explained in more detail hereinafter, upon rotation of rotor 24 in response to closing of door 16, detent 44 is moved into the trace of face 40, whereby to block return rotation of rotor 24, and thereafter detent 46 is moved into the trace of face 42, whereby to further block return rotation of rotor 24.

In the embodiment shown, rotor 24 is a laminated structure comprised of two plates 48 and 50 held in face to face relation as by rivets 52.

Plate 48, the foremost plate as viewed in FIGURE 2, in addition to providing the above described arms 28 and 30 and throat 32, also provides radial face 42. Plate 50, the plate as viewed in FIGURE 2, provides radial face 40 and also includes an arm portion 51 projecting beyond the periphery of plate 48 to provide a tail for engagement of rotor return spring 25. Faces 40 and 42 are thus disposed in different planes so that detents 44 and 46 may pivot side by side about a common pin 54 secured to the door frame.

With the latch in the unlatched condition of FIGURE 2, follower arm 43 of detent 44 is urged by a spring 58 against a follower surface 60 provided by a peripheral portion of plate 50 adjoining face 42 and follower arm 45 of detent 46 is urged by a spring 62 against a follower surface 64 provided by a peripheral portion of plate 48 adjoining face 40. Spring 58 engages a radial arm 66 of detent 44 and wraps around a pin 68 secured to the door frame and spring 62 engages a tab 70 constituted by the folded over end of a radial arm 71 of detent 46.

When door 16 is closed to This latched condition of the rotor is shown in FIGURE 3, to which reference is now again made. As seen in that figure, the detent arm 43, since it has been moved well beyond face 40, cannot be hung up on that face but rather must of necessity be firmly planted in the peripheral trace of that face. Thus, even if arm 45 should hang up on face 42 upon closing of the door and thereafter be shaken loose from that tooth to release rotor 24, the rotor will be positively caught by the subsequent firm abutment of the butt end of detent arm 43 against face 40. The latch of the invention thus acts to prevent opening movement of the door beyond the safety position even under severe shock conditions.

The above described double detent construction of the invention also enables the rotor detent follower surfaces to be laid out in a manner to provide smooth and positive latch operation. Thus, and with continued reference to FIGURES 2 and 3, the follower surfaces 60 and 64 are laid out as concentric circular arcs centered about the axis of pin 26. With this construction, as the detents ride along the follower surfaces during closing of the door, they remain absolutely static and move smoothly and positively into the trace of the respective radial face upon reaching the end of the respective followersurface. This construction thus eliminates most of the dynamic force factors inherent in the bouncing movement of the single detent of the prior art constructions, thereby prolonging effective latch life and assuring position latch operation even under widely varying operational and/or climatic conditions.

Means are also provided according to the invention for gradually decelerating each detent to its rest position withseen in FIGURES 2 or 3, each detent 44, 46 includes a radial brake arm 72, 73. A pad 74, formed of any suitable cushioning material such for example as sponge rubber, is suitably secured to the door frame in a position in the path of pivotal movement of brake arms 72, 73. As follower arm 43 drops off the end of follower surface 60 and is propelled by spring 58 radially inwardly into the trace of face 40, brake arm 72 is moved against cushion 74 to prevent arm 43 from slapping noisily against the adjacent underlying peripheral surface 76 of rotor plate 50. Similarly, as follower arm 45 drops off the end of follower surface 64 and is propelled by spring 62 radially inwardly into the trace of face 42, brake arm 73 is moved against cushion 74 to prevent arm 45 from slapping noisily against the adjacent underlying peripheral surface 78 of plate 48. The latch of the invention is accordingly extremely quiet in operation.

The latch may be moved from its latched :position of FIGURE 3 to the unlatched push button 80 (FIGURE 1) or by operation of the usual inside door handle (not shown).

Depression of push button 80 pivots (by a linkage not shown) a bell crank 82 clockwise (as viewed in FIGURE 3) about pin 54 to press the free end 84 of crank 82 against a tab 86 constituted by the folded over end of an arm 88 upstanding from 'brake arm 72. Further depression of button 80 pivots detent 44 clockwise to move follower arm 43 upwardly; pivotal movement of detent 44 in turn presses a coupler bar 90 carried on the underside of brake arm 72 against the upper edge 92 of a notch cut in the underside of brake arm 73 so that detent 44 is first moved a short distance by itself whereafter detents 44 and 46 are coupled together for joint pivotal movement. This arrangement ensures that the safety follower arm 43 will be clear of radial face 40 by the time primary follower arm 45 clears face 42 so that rotor 24, once released, will move smoothly and without interruption to its fully unlatched position. This fully unlatched position is determined by engagement of radial face 42 with a cushioning pad 94 mounted on the door frame. As the rotor 24 moves toward its unlatched position under the urging of spring 25, throwout arm 30 ejects striker from throat 32 to allow the door to be moved to its fully open position.

As best seen in FIGURE 4, operation of the inside door handle slides (by a linkage not shown) a slotted lever 96 upwardly on pin 68. Lever 96 has a transversely extending end portion 98 which, as the lever is moved upwardly, engages the underside of radial arm 66 of detent 44 to pivot follower arm 63 upwardly, whereafter, in the manner previously described with reference to push button 80, coupler bar 90 picks up detent 46 to release rotor 24.

While a preferred embodiment of the invention has been illustrated and described in detail it is to be understood that various changes may be made in the disclosed embodiment without departing from the scope or spirit of the invention as defined in the appended claims. Specifically, although the invention has been described with reference to an automobile door, it will be understood that it has application and usefulness wherever it is desired to latch a swinging member to a fixed member. Further, although the disclosed embodiment of the invention employs a rotary bolt, the invention may also be practiced to advantage with a reciprocal or sliding bolt.

I claim:

1. A mechanism for latching a swinging member to a fixed member comprising:

(A) a bolt on one of said members (1) mounted for movement in a given direction along a predetermined path from an unlatched position to a latched position, and

(2) presenting first and second surfaces each having a substantial extent in a direction transverse to said path;

(B) coacting means bers operative in on said swinging and fixed memresponse to closing of said swinging member on said fixed member to move said bolt said given direction from its said unlatched position to its said latched position;

(C) first and second detents positioned along said path and mounted on said one member for movement between an unlatched, rest position and a latched position within the trace of said first and second surfaces, respectively;

(1) said detents being positioned with respect to said surfaces such that, in response to the aforesaid movement of said bolt along said path, only said first surface intersects the path of movement of said first detent and only said second surface intersects the path of movement of said second detent; and

(D) means operative in response to movement of said first and second surfaces past said first and second detent-s, respectively, to move said first and second detents into their latched positions within the trace of said first and second surfaces, respectively, whereby to block return movement of said bolt.

2. A latch mechanism according to claim 1 and further including:

(A) means operative to gradually decelerate each detent to its latched position within the trace of the related surface, whereby to eliminate slapping of the detents against said bolt. 7

3. A mechanism for latching a swinging member to a fixed member comprising:

(A) A rotor on one of said members (1) mounted for rotation in a given direction from an unlatched position to a latched position, and

(2) presenting first and second surfaces each having a substantial radial extent;

along said path in (B) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said bolt in said given direction from its said unlatched position to its said latched position;

(C) first and second detents positioned adjacent the periphery of said rotor and pivotally mounted on said one member for pivotal movement between an unlatched rest position and a latched position within the trace of said first and second surfaces, respectively,

(1) said detents being positioned with respect to said surfaces such that, in response to the aforesaid rotation of said rotor in said given direction, only said first surface intersects the path of pivotal movement of said first detent and only said second surface intersects the path of pivotal movement of said second detent; and

(D) means operative in response to movement of said first and second surfaces past said first and second detents, respectively, to pivot said first and second detents into their latched positions within the trace of said first and second surfaces, respectively, whereby to block return movement of said rotor.

4. A latch mechanism according to claim 3 and further including:

(A) means operative to gradually decelerate each detent to its latched position within the trace of the related surface, whereby to eliminate slapping of the detents against said rotor.

5. A mechanism for latching a swinging member to a fixed member comprising:

(A) a rotor on said swinging member mounted for rotation in a given direction from an unlatched position, in which said rotor is free to rotate in the direction opposite to said given direction, to a latching position, in which said rotor is blocked from rotation in said opposite direction, said rotor defining at its periphery,

(l) a first follower surface followed, upon rotation of said rotor in said given direction, by a first radially inwardly extending surface, and

(2) a second follower surface followed in said given direction of rotation by a second radially inward extending surface;

(B) first and second detents positioned on said swinging member to respectively engage said first and second follower surfaces with said rotor in its said unlatched position;

(C) spring means normally urging said first and second detents radially inwardly against said first and second follower surfaces, respectively; and

(D) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said first member to rotate said rotor in said given direction, whereby said first and second detents slidably follow said first and second follower surfaces, respectivcly, and move under the urging of said spring means radially inwardly into the trace of the related inwardly extending surface as the latter is moved therepast.

6. A latching mechanism according to claim 5 wherein:

(A) each of said follower surfaces lies on a circular are centered on the axis of rotation of said bolt, whereby said detents remain static during the aforesaid sliding movement along said follower surfaces.

7. A latching mechanism according to claim 5 and further including:

(A) a cushion for each detent located in a position to be engaged by a portion of that detent upon the aforesaid radially inward movement thereof whereby to prevent slapping of said detents against said rotor.

8. A mechanism for latching a swinging member to a fixed member comprising:

(A) a rotor on said swinging member defining at its periphery (1) a first follower surface followed, upon rotation of said rotor in a given direction, by a first radially inwardly extending surface, and

(2) a second follower surface axially, angularly adjacent said first follower surface and followed in said given direction of rotation by a second radially inwardly extending surface;

(B) first and second adjacent detents mounted on said swinging member;

(C) spring means normally urging said first detent radially inwardly against said first follower surface at a location thereon relatively near said first radially inwardly extending surface;

(D) spring means normally urging said second detent radially inwardly against said second follower surface at a location thereon relatively distant from said second radially inwardly extending surface; and

(E) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said rotor in said given direction, whereby said first and second detents slidably follow said first and second follower surfaces, respectively, and first said first detent and thereafter said second detent move under the urging of said spring means radially inwardly into the trace of the relative inwardly extending surface as the latter is moved therepast.

9. A mechanism for latching a swinging member to a fixed member comprising:

(A) a rotor on said swinging member defining at its periphery (1) a first follower surface followed, upon rotation of said rotor in a given direction, by a first radially inwardly extending surface and (2) a second follower surface axially, angularly adjacent said first follower surface and followed in said given direction of rotation by a second radially inwardly extending surface;

(B) first and second adjacent detents mounted on said swinging member;

(C) spring means normally urging said first detent radially inwardly against said first follower surface at a location thereon relatively near said first radially inwardly extending surface;

(D) spring means normally urging said second detent radially inwardly against said second follower surface at a location thereon relatively distant from said second radially extending surface;

(E) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said rotor in said given direction, whereby said first and second detents slidably follow said first and second follower surfaces, respectively, and first said first detent and thereafter said second detent move under the urging of said spring means radially inwardly into the trace of the related inwardly extending surface as the latter is moved therepast; and

(F) a cushion for each detent located in a position to be engaged by a portion of that detent upon said radially inward movement thereof, whereby to prevent slapping of said detent against said rotor.

10. A latch mechanism according to claimr9 wherein:

(A) each detent is multi-armed and (1) one arm of each detent is arranged to move as afore-described into the trace of the related radially extending surface and (2) the cushion for each detent is located in the path of pivotal movement of another arm of that detent.

11. A mechanism for latching a swinging member to a fixed member, comprising:

(A) a rotor on said swinging member defining at its periphery a follower surface lying on a circular are centered on the axis of rotation of said rotor and followed, upon rotation of said rotor in a given direction, by a radially inwardly extending surface;

(B) a detent;

(C) spring means normally urging said detent inwardly against said follower surface;

(D) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said bolt in said given direction, whereby said detent slidably and statically follows said follower surface and moves under the urging of said spring means radially inwardly into the trace of said inwardly extending surface upon movement therepast; and

(E) means operative to gradually decelerate said detent to its rest position within the trace of said inwardly extending surface, whereby to eliminate slapping of said detent against said bolt.

12. A mechanism for latching a swinging member to a fixed member comprising:

(A) a bolt on said swinging member presenting first and second laterally adjacent surfaces each having a substantial extent in a direction transverse to the path of movement of said bolt;

(B) first and second adjacent detents on said swinging member normally positioned adjacent said path;

(C) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to move said bolt along said path from a rest position through a distance sufficient to move said first and second surfaces past said first and second detents respectively; and

(D) means operative l) in response to the aforesaid movement of said first surface past said first detent to move the latter to a position within the trace of said first surface, whereby to block return movement of said bolt, and

(2) in response to the aforesaid movement of said second surface past said second detent, to move the latter to a position within the trace of said second surface, whereby to further block return movement of said bolt,

(3) said detents and surfaces being arranged so that said first surface is moved past said first detent before said second surface is moved past said second detent so that said first detent is moved to a position spaced from said first surface at such time as said second detent is moved into the trace of said second surface.

13. A mechanism for latching a swinging member to a fixed member, comprising:

(A) a rotor on said swinging member presenting first and second angularly, laterally adjacent surfaces each having a substantial radial extent;

(B) first and second adjacent detents on said swinging member normally positioned adjacent the periphery of said rotor;

(C) coacting means on said swinging and fixed members operative in response to closing of said swinging member on said fixed member to rotate said rotor through an angular distance first and second surfaces circumferentially past said first and second detents; and (D) means operative (1) in response to the aforesaid movement of said first surface past said first detent to move the latter to a position within the trace of said first surface, whereby to block return rotation of said rotor, and

(2) in response to the aforesaid movement of said second surface past said second detent, to move the latter to a position within the trace of said second surface, whereby to further block return rotation of said rotor,

(3) said detents and surfaces being arranged so that said first surface is moved past said first detent before said second surface is moved past said second detent so that said first detent is moved to a position spaced circumferentially from said first surface at such time as said second detent is moved into the trace of said second surface.

References Cited UNITED STATES PATENTS Johnson et a1. 123-43 Rightmyer 292-210 X Roethes 292-366 X Dall 292-6 Baker 292-280 Nadeau 292-216 Davies 292-229 Van Voorhees 292-11 RICHARD E. MOORE, Primary Examiner. 

